1. Field of the Disclosure
The disclosure relates to an antenna and a communication device thereof.
2. Description of Related Art
Along with increasing demands for quality and transmission speed in wireless communication, multi-antenna systems such as a pattern diversity antenna system or a multi-input multi-output antenna (MIMO) system are vigorously developed. In comparison with a single-antenna system widely applied in communication devices, the MIMO antenna system designed with a plurality of transmitting and receiving antennas may improve wireless data transmission speed, which is an important development trend in future communication devices. For example, a wireless local area network (WLAN) system, a universal mobile telecommunication system (UMTS), a worldwide interoperability for microwave access (WiMAX) system and a 4th generation mobile communication system such as long term evolution (LTE) system are all developed to be capable of supporting and implementing the MIMO communication technique.
To design a multi-antenna architecture with good energy or ports isolation is a technical challenge that may not easily be achieved. Since electromagnetic energy radiated by multi-antenna elements being operated in a same frequency band may be liable to have severe mutual coupling effects, it is difficult to achieve good energy or ports isolation between the multi-antenna elements. Conventionally such as designing the adjacent antenna elements to be orthogonal to each other, designing protruding or open slot structures on the ground area between nearby antenna elements, or increasing the distance between adjacent antenna elements to improve the energy or ports isolation there between, may in turn additionally increase overall size of the multi-antenna system. Therefore, how to achieve the multi-antenna architecture within a limited usable antenna space of the communication device is an important technical research and development topics of recent years.